Straightedge and cutter guide



April 15, 1941. F, E. EDGRENv 2,238,558

STRIGHTEDGE AND CUTTER GUIDE Filed April 15. 1940 Patented Apr. 15, 1941 UNITED STATES PATENT OFFlCE STRAIGHTEDGE AND CUTTER. GUIDE Fred E. Edgren, Chicago, Ill.

Application April 15, 1940, Serial No. 329,758

4 Claims.

My invention relates to straightedges employed by paper hangers in trimming wall paper and the like and relates more especially to combined straightedges and cutter guides made of extruded metal possessing the required strength and rigidity and in connection with which the standard trimming devices may be employed.

The invention has for its object the provision of a straightedge with a removably attached cutter guide, also formed of comparatively light and preferably extruded metal, which will be unaffected by climatic conditions and will maintain its original true condition.

Another object of the invention is the provision of a straightedge wherein the cutter guide is firmly secured to the main body of the straightedge so as to leave a smooth, unobstructed forward or trimming face and wherein the downward pressure, exerted through the use of the paper trimmer or in maintaining a true nonshifting relation with the paper, will be applied to both units of the device without subjecting the fastening elements or screws to improper or shearing strains, thus enabling the cutter guide unit to be readily removed for resurfacing or renewal in the event the guide unit has become marred or damaged.

The invention and its objects will be readily understood from the following detailed description of the accompanying drawing wherein:

Figure l is a perspective view of a portion of a straightedge embodying my invention.

Figure 2 is a similar view showing a modified form.

Figure 3 is a perspective view of a portion of a straightedge embodying another modication.

Figure 4 is a similar view illustrating a further modified form.

My invention relates to straightedges preferably made of extruded metal and composed of two units-a main body portion and a cutter guide portionformed with matching or interengaging surfa'ces whereby `downward pressure on the cutter guide unit will be directly transmitted t the main body unit; the two units being formed to provide a suitable guide-way or channel for the usual trimming tool or cutter; the two units being secured together by suitable fastening elements introduced through a noncontacting surface of the straightedge.

The embodiment of the invention illustrated in Figure 1 consists of the body unit Ill, preferably made of extruded metal-although it may be made of iibrous or moulded plastic material-and of any desired length and of comparatively narrow dimensions as is usual in straightedges of the character in question. It is also essential that the straightedge not be of excessive weight and yet possess the requisite strength and hence the rear longitudinal edge is shown provided with a flange II having a flat surface to provide a proper bearing on the paper to be trimmed without marring the paper and also aioid a continuous true contact with the paper; while the forward longitudinal side of the body IU is of greater thickness and is vertically offset beneath the plane of the top surface of the body portion, as p shown at I2. The lower surface of the enlarged portion I2 is chamfered or recessed at its forward edge to a predetermined extent to receive the lower side or leg I3 of the track or cutter guide unit I4 which is of channel-like formation; the recess in portion I2 being of sufficient depth to permit the lower leg or side I3 of track unit I4 to extend flush with the bottom of the enlarged portion I2.

The depth of the track channel Ill is less than the width of the enlarged portion I2 in order that the inner longitudinal edge of the upper side or leg I5 will be in horizontal spaced relation with the shoulder I6 formed in the body unit by offsetting the enlarged forward portion I2. The upper side or leg I5 throughout a considerable portion of its width has at bearing on the upper surface of enlarged portion I2; while the portion of the side or leg I5 adjacent the inner longitudinal side of the track or guide unit I4 is of reduced thickness and arranged in vertical spaced relation with the top of the enlarged Aportion I2 of the main or body unit and thus provides a, trimmer receiving slotway; the spacing between the inner edge of leg I5 and the shoulder it being sufficient to enable the introduction of the trimming d-evice into the slotway beneath the upper side or leg I5 of the cutter guide unit I4.

The guide unit I4 is shown secured to the body unit I9 by means of a plurality of screws I'I which extend upwardly through the lower leg or side I3 of unit I4 and into the thickened or enlarged portion I2 of the main unit Ill; the screws I'I are preferably countersunk so as to leave a smooth uninterrupted lower surface on the guide or track unit I4; the cutter or track unit I 4 and the enlarged portion I2 affording a wide bearing surface which will not injure or mar the paper during trimming operation, as, however, is the case where comparatively narrow bearing surfaces at the forward pressure receiving edge of the straightedge are formed.

As is apparent from the drawing, the downward pressure exerted by the cutting tool, while sliding along the guide or track unit I4, will be placed on the enlarged portion I2 which is provided with a wide bearing surface on its bottom. It is also to be noted that the bottom surface of the enlarged po-rtion I2 with th-e countersunk or inset leg or side I3 of the cutter guide unit I4 preferably is disposed in the same plane as the bottom surface of the flange I I; and with the fastening screws I'I entering from beneath a smooth uninterrupted forward side is provided for the paper trimming knife or rotating disc of the paper tirmming tool which travels in close contact with the outer face of the unit I4.

In Figure 2, the main body unit 20 at its rear longitudinal edge also has a flange II, while the forward longitudinal side has an extension 22 vertically offset beneath the top surface of the unit 2U and extending into the horizontal plane of the flange II. The extension 22 is substantially similar to extension or enlargement I2 of Figure 1 except that the enlargement or extension 22 is slightly reduced on its inner side and beveled as shown at 23 and provided with tapped holes inclining upwardly toward the forward side of extension 22 to receive screws I1 whereby the guide unit 24 is secured in place. The guide unit 24 is of the nature of an angle with one side or leg flush with the forward side and the bottom of the extension 22, while the other side or leg rests on the upper surface of the extension and is reduced in thickness at its longitudinal edge as shown at 25 to provide a cutter tool receiving slotway therebeneath. The top leg or side of the guide unit 24 terminates at a distance removed from the shoulder 2'5 o-f the main or body unit 2U to enable introduction of the cutting tool into the slotway beneath the top leg or side of the guide unit 24.

The extension or enlargement 22 in conjunction with the lower edge of the track or guide unit 24 provide a comparatively wide bearing surface which is not apt to injure or mar the wall paper during trimming operation.

Figure 3 illustrates wherein the main or body unit 3B at its rear longitudinal side also is provided with a depending flange I I, while the forward longitudinal edge is formed with a downwardly and forwardly sloping extension 3| which terminates at the bottom in a horizontally disposed base portion 32. The forward side of the extension 3| at its top and beneath the top of the main body portion has a horizontally disposed portion 33; and at a point between the top and the bottom is provided with a longitudinally disposed groove 34 which receives the rib 35 which extends longitudinally of the inner face of the track or guide unit 36; the inner face of unit 36 being made sloping to match the outwardly sloping face of the extension 3|. The track unit 3E is provided with a flat lower surface arranged flush with the base portion 32 of main unit 30, to provide a wide paper engaging surface; and the top of the guidev unit 36-which extends in the same horizontal plane as the top of the main unit 30-at its inner longitudinal side is reduced in thickness to provide the undercut groove 3l and this top inner longitudinal side or edge terminates short of the body unit to permit insertion of the usual guide member of the paper cutting tool into the undercut groove 3l. The track or guide unit 36 is removably secured to the main or body unit 30 by suitable screws I'I which extend thro-ugh the enlarged portions of the extension 3I and another modification l of the guide unit 36, namely, preferably through the tongue and groove interengaging portions of the two` units and the heads of the screws, as in the previously described constructions, being preferably countersunk.

As is apparent from the construction shown, the downward pressure exerted on the trimmer or cutting tool will be transmitted to the extension of the main or body unit by reason of the interengagement and hence will not be exerted on the screws.

The modification illustrated. in Figure 4 is substantially similar to that shown in Figure 2, with the body unit 4I) also provided at its rear longitudina1 edge with a depending flange II and the forward longitudinal edge provided with the extension 4I extending horizontally forward beneath the top of the body unit 4i! and terminating in the base portion 42 disposed in the horizontal plane of flange II; while the upper outer edge of the extension 4I is cut away or beveled at 43 in order to reduce the weight of the structure. The lower side of the extension 4I, coincident with the bevel 43, is shown sloping and is provided with tapped holes to receive the fastening screws I1 whose heads also are preferably countersunk, while the threaded ends of the screws extend into the body portion of the vtrack or guide unit 44 which is in the nature of an angle with its upper side or leg resting on the horizontal top face of the extension 4I and its top face arranged in the plane of the top surface of the body unit 4U. The top leg of unit 44 terminates short of the shoulder 45 formed at the forward edge of the body unit and this top is reduced in thickness at its longitudinal edge to provide the undercut groove 4S to receive the guide foot or portion of the usual cutting tool.

The various forms of my improved straightedge are preferably made of extruded metal and of comparative thickness to provide sufcient rigidity, I am aware that straightedges of extruded metal have been made with the track or cutter guide portion made integral with the main body portion, but straightedeges of that type not only are difficult to accurately manufacture but also rather expensive in `manufacture because definite measurements must be maintained to adapt the straightedge to the present day paper trimmers which are all made to standard measurements to maintain the trimmer or knife snugly against the forward face of the straightedge. In the event the forward or track edge of the single piece straightedge becomes indented it is evident that the forward face could not be machined to take out indentations or inaccuracies because such machining would decrease the required dimensions. With my improved straightedge, the track or guide units may be readily removed and replaced if necessary without incurring the expense of an entirely new straightedge; my improved straightedge permitting Y proper pressure to be placed thereon without bes ing entirely exerted on the guide units, while at the same time presenting a proper edge for firmly holding the paper to be trimmed.

What I claim is:

1. A straightedge of the character described comprising a single piece metallic body unit and a single piece metallic track or guide unit; the body unit at its rear longitudinal edge having an integral depending ange to provide a bearing surface and at its forward longitudinal side being provided with a forwardly disposed extension offset vertically beneath the plane of the main body to provide a bearing surface while the track unit on its inner side is formed to match and receive said extension, the top and bottom surfaces of the track unit being disposed in the planes of the top of the main body unit and of the bottom of said extension, with the inner longitudinal edge of the top portion of the track unit undercut and arranged in lateral spaced relation vwith sthe top of the body unit and in vertical spaced relation with the top surface of said extension to provide a cutter tool receiving slotway; and removable means disposed upwardly from the lower side of the straightedge for removably securing the track unit in place.

2. A straightedge of the character described comprising a single piece body unit provided at its forward Ilongitudinal side and beneath its top surface with an extension having a flat bearing surface on its bottom; a single piece track or guide unit of angular cross-section having an inner face made to match said extension and said matching face being so arranged that downward pressure on the track unit will be transmitted to said extension, While the top and bottom surfaces of said guide unit extend flush with the upper surface of the body unit and flush with the bottom surface of said extension, the top portion of the track unit being spaced from the main portion of the body unit and undercut to provide a cutter tool receiving slotway; and fastening elements extending upwardly from the lower side of the straightedge whereby the guide unit is removably secured in place.

3. A straightedge of the character described comprising a single piece body unit provided with an integral downwardly disposed flange at the rear longitudinal edge and with an integral forwardly disposed extension at the forward longitudinal side at a predetermined distance below the top surface of the main portion of the body unit; a single piece track or guide unit of angular cross-section, the inner face of the guide unit being formed to match the body unit extension, certain portions of the matching surfaces being arranged in overlapping relation so `that the downward pressure exerted on the track unit by the cutting tool will be directly transmitted to the main body unit, the Abotto-rn of said extension and the track unit combinedly forming a wide paper engaging surface; and fastening elements extending upwardly from the lower side of the straightedge whereby the two units are removably secured together.l

4. A straightedge of the character described composed of a body unit and a track or guide unit of extruded metal, the opposing sides of the two units having matching surfaces with certain portions of said surfaces on both units arranged at right angles to the adjacent portions of said surfaces whereby downward pressure on the track unit will be directly transmitted to the body unit in a similar direction, the top and bottom surfaces of the track unit being disposed in the horizontal planes of the top and bottom surfaces of the adjacent portions of the body unit, the juncture between the two units being formed to provide a cutting tool receiving slotway on the upper surface of the straightedge and the juxtaposed' portions of both units at the bottom formed to provide fiat bearing surfaces; and means whereby the two units are secured together.

FRED E. EDGREN. 

